ArbOS 40 “Callisto” is now live on Arbitrum One and Nova! This upgrade brings new capabilities from @Ethereum’s Pectra hard fork including: EIP-7702 (Account Abstraction) EIP-2537 (BLS Precompile) EIP-2935 (Block Hash Access) And a minor Stylus fix for devs Let’s dive in 👇

ArbOS 40 also integrates EIP 2537, native BLS Precompiles This EIP introduces precompiles for cryptographic ops on the BLS12-381 curve boosting efficiency and security 120+ bits of security (vs 80 w/ BN254) Enables BLS sigs, zkSNARKs, randomness, vector commitments, & more Big boost for zk + light client use cases

EIP-2935: Access to Recent Block Hashes Adds access to recent block hashes on L2 and improves Trustless messaging Oracle syncing L2 stateless clients This allows for more accessible and trustless historical data retrieval for Arbitrum chains

Minor Stylus VM Caching Fix ArbOS 40 also includes a fix to the Stylus VM’s handling of non-existent contracts in cache lookups - calls to account_code or account_code_size now reflect the current state, even for addresses where a contract did not previously exist This makes developer workflows smoother for Rust builders on Arbitrum